The surface of the Earth’s oceans is in constant motion, moving up and down in the form of waves. If you have been to a beach, you have witnessed waves first hand.
Waves form as energy is transferred from molecule to molecule across the surface. In general, the water molecules move very little. It is only the energy that actually moves.
However, as waves break across a shore or crash in violent storms, they can be the source for great mixing of an ocean’s water.